Gamma-aminobutyric acid, or GABA, is the main inhibitory chemical messenger in the central nervous system. Its function is to slow down brain activity by blocking specific signals between nerve cells, producing a calming effect. This action helps manage feelings of anxiety, stress, and fear, and it acts as the brain’s braking system to prevent overstimulation.
The Function of GABA in the Nervous System
GABA carries out its role by binding to specialized proteins on neurons called GABA receptors. When GABA attaches to these receptors, it changes the neuron’s membrane potential, making it less likely to fire. This process, known as hyperpolarization, reduces the excitability of the nervous system.
The nervous system maintains an equilibrium between stopping and starting signals. The main counterpart to GABA is glutamate, the most abundant excitatory neurotransmitter. While GABA acts as the “brakes,” glutamate functions as the “gas pedal,” increasing the likelihood that a neuron will become active. This dynamic relationship modulates the brain’s overall activity level.
By reducing neuronal activity, GABA helps regulate mood, ease stress, and prepare the brain for sleep. Its ability to control nerve cell hyperactivity allows for a state of calm. This balance also affects physical functions like muscle tone, as deficits in GABA can lead to excessive muscle stiffness.
Signs of GABA Imbalance
When GABA activity is insufficient, the nervous system’s “braking” system becomes less effective. This can lead to over-excitation, where nerve cells fire too often. The consequences of this imbalance can manifest as psychological and physiological symptoms, including a persistent feeling of unease or nervousness.
This heightened neuronal excitability can contribute to feelings of anxiety, chronic stress, and irritability. Individuals may experience restlessness or an inability to relax. This can also impact cognitive functions, leading to difficulty concentrating and memory problems as the brain is overwhelmed with signals.
Sleep disturbances, particularly insomnia, are also associated with low GABA activity. The neurotransmitter helps the brain transition into a relaxed state required for sleep. Without adequate GABAergic inhibition, the brain can remain alert, making it difficult to fall asleep and stay asleep.
GABA Supplements and the Blood-Brain Barrier
A point of discussion surrounding GABA is the use of oral supplements to increase its levels in the brain. The primary challenge is the blood-brain barrier (BBB). This barrier is a network of blood vessels and tissue that protects the brain from foreign substances, preventing most compounds, including supplemental GABA, from passing into the brain.
For decades, the scientific consensus was that supplemental GABA could not cross this protective barrier. However, more recent research has introduced nuance to this view. Some studies suggest the possibility of transport across the BBB, though the mechanism and extent are not fully understood.
Despite the uncertainty about crossing the BBB, some individuals report calming effects from taking GABA supplements. One theory proposes that GABA may influence the enteric nervous system (ENS), the network of neurons in the gut wall. The gut and brain are connected through the vagus nerve, so GABA could act on the ENS, which then signals the central nervous system. Another possibility is that some individuals have a more permeable BBB, allowing small amounts of GABA to enter the brain.
Medications and Natural Methods that Influence GABA
Certain pharmaceutical drugs are designed to influence the body’s natural GABA system. Benzodiazepines, a class of drugs including diazepam and alprazolam, bind to a specific site on the GABA-A receptor. This action enhances the effect of the brain’s own GABA, amplifying the natural calming response. Barbiturates and alcohol function similarly.
Beyond pharmaceuticals, various lifestyle practices can support the body’s GABAergic system. Physical activities like yoga and exercise have been shown to increase GABA levels in the brain. Mind-body practices such as meditation also contribute to a reduction in stress, which may be linked to their influence on the GABA system.
Dietary choices can also play a supportive role, as GABA is synthesized in the body from glutamate. Consuming foods rich in this precursor, such as those high in protein, provides the necessary building blocks. Additionally, some fermented foods, including kimchi, miso, and certain yogurts, contain GABA produced by microorganisms.